Airplane engine nacelle



D. B. SUG-Gs 2,435,168

AIRPLANE ENG INE NACELLE Filed Nov. 2o, 1944 5 sheets-sheet 1 D. B.SUGGS AIRPLANE ENGINE NACELLE Jan. 27, 1948.

5 Sheets-Sheet 2 Filed Nov. 20, 1944 j. 27, l. D. B, sUGGs AIRPLANEENGINE NACELLE Filed Nov.` 20, 1944 3 Sheets-Sheet 5 Patented Jan. 27,1948 p 2,435,168. MRPLANE; ENGINE Nncmmn Dalton B1 Suggs, Fort: WorthTex., assignox: to Consolidated Vultea Aircraft ('Jorporation, SanDiego* Calif., a corporation of Delaware.

Application Novem-lierI 20, 1944, Serial No. 564,393'

SaClaims. 1a

The present invention relates generallyI tot` V11a-- celles forairplanes. More particularly* the-imm vention relates to that type. ofairplane. nacelle which serves 'as aglio-using 'medium for the lpio-Ipalier driving engine 'ofthe airplane and is 'adapt--A edunder certainconditi-ons to have air flow through it in orderI to. cool: the enginethe absorption of heat therefrom. l

YOnerohject ofA` the invention is: to provide an airplane engine nacelleor this, type which is clesigned. and arranged so that theend thereofthat is adjacent the propeller is spaced outwards theconnentionalspinner on the propeller lztuhv and forms an annular air opening there--with. and has. associated with it novell means for controlling therlovv4 of air through the annular air .opening inorder to regulate thevolume of cooling air which is passed over the engine with in thenacelle.

Anotherobectof the invention is to provi-de an airplane engine nacelleof the lastrmentionedcharacter in which the mea-nsl for controlling theow of air through the annular air4 opening is in the form of an annularplug ap which is of airfoil cross. section and is mountedvconcentrical'ly within thev nacelle so. that itis shiftable axiallyA to:and from a closed position wherein it fills or closes the. air openingbetween the pro pellerl spinner andl the adjacent end of the nacelle.

A further object of the invention is to provide in connection with anacelle of the type and character underv consideration simple and novelmeans for shifting the annular plug flap into and out of its closedposition.

AV still further object` of the invention isto provide an airplaneengine nacelle which is genorally of new and improved construction andischaracterized by extremely high efciency so far as the control of airtherethrough. for engi-ne cooling'purposes is concerned..

Other objects of theinvention and thevari ons advantages andcharacteristics of the. present. airplane engine nacelle will beapparent. from a consideration'oi the following detaileddescrip tion.

The invention consists in the several novel features which .arehereinafter set forth and are more particularly defined by claims atvthe com clusion hereof.

In the drawingswhich accompany and form. a: part of this specificationor disclosure andV in which like letters and numerals of referencedenote corresponding parts throughout the several views:

Z Figure; l is a, perspective: view of a. pusher type airplane havingapp-lied thereto. an. engineJ nacelle embodying the invention :a

Figure, 2 is a. vertical transverse section through.

the nacelle;l

Figure 3 `is a'longitudinal section taken. on the,

line. 3-3 of Figure 2 and illustrating; in detail? the construction and.design ci the axially. shift. able. ping flap which serves to controlthe` flow of air through the; annular; air opening between. thepropeller spinnerv and the adjacent; endoil the nacelle; y

Figure 4 is a longitudinal: section on, the line 4;--4 of Figure 3;- andFigures 4c and 4h are enlarged cross sections taken respectively onthe.y lines llc-. -li andy 4b....4b. of; Figure 3v and showingind'etail' one orl the parts or units of the mechanism for shiftingthelplug iiap to and from the annular airopening for air flow controllingpurposes..

The nacelle which. is shownv in the. drawings: constitutes; the preerredform ory embodiment. of the invention. It is designated by the referencenumeral 5 and is; illustrated in connection with, and' as forming a partof, a pusher type,- airplane A. The latter embodies. a fuselage a;having a wing structure alA at; its, sides for sup.-` porting purposes..The rear end of' the. fuselage. a is provided with an. engine a2 andthis is con.` nected to drive a propeller a?. As show-n. in thedrawingsIr the propeller is located directly' be..- hind; the engine andhas at its hub portion a. rearwardly tapered conoidal spinner c4, Thenacelle. 5 surrounds andserves. as a. housing medium for the propellerdriving engine a2 and istubulary in, form. of the iuselage. a, and hasat its irontv en d an. air inlet.. (not, shown). In general the nacellelis circular in cross section. The rear or trailine end of the nacelleis. rearwardly taneredand has its end edge positioned. adjacent and in,spaced relation .around the. front end; or thev spinner of? in. orderto'iorm between it and the, spinneran: annular air opening E.i When theairplane A is in operation air enters they nacelle. 5 va theaforomentioned inlet at the iront, end oi the nacelle.

nacellev it ilovrs aroundA 'and past the. engine .ci

and eieots. cooling of; the latter bv the absorption of heat therefrom.A ring shaped stiflener '1 is fixedly secured to the inner periphery ofthe.

rear or trailing end of the nacelle 5. as best shown in Figure. 2` Thisstlener assists in dennins the It is suitably connected tothe rearendannular air opening 6 and is streamline in contour for aerodynamicreasons.

Associated with the nacelle is an annular plug flap 8 and this isdisposed concentrically Within the rear end of the nacelle and serves asa valve instrumentalityor medium for controlling the flow of air throughthe annular air opening 6. As shown in the drawings the plug nap B is ofairfoil cross section and has a transversely curved or rounded frontend. The rear or trailing end of the plug flap is rearwardly tapered.The plug flap is mounted so that it is shiftable axially into and out ofa closed position wherein the central or intermediate portion thereofsubstantially fills or closes the air opening 6; The mounting for theplug flap comprises a plurality of brackets 9 and a corresponding numberof screw shafts I. Preferably there are four brackets 9 and these areconnected to. and project radially outwards from, the leading end of theplug flap 8, The brackets consist of narrow arm-like intermediate parts9a, attachment plates 9b at the inner ends of the parts 9a, and outnWardly extending bifurcated or fork-like members 9c at the outer ends ofsaid parts 9e. The attachment plates 9b are shaped conformably to theleading end of the plug flap 8 and are welded or otherwise fixedlysecured thereto. The screw shafts Ill are located adjacent the outerends of the brackets 9 and are disposed Within, and extendlongitudinally of, the nacelle 5. They are arranged in parallel relationand are operatively connected to the fork-like members 9c of thebrackets. by nuts II. The latter fit Within, and are suitably securedto, said fork-like members 9 and are mounted on the shafts l0respectively. When the shafts are conjointly rotated in one directionthey operate through the medium of the nuts to shift the plug flap 8rearwards into its closed position wherein the central portion thereofis disposed Within the annular air opening 6.

Conjoint reverse rotation on the part of the screw shafts |Ii results inthe plug flap 8 being shifted forwards into its open position. Byturning the screw shafts the plug flap may be shifted forwards orrearwards with respect to the air opening 6 into any desired positionwherein it serves in the desired manner to control the volume of airpassing rearwards through the opening and thus regulates the heat of theengine a2. The screw shafts I8 are ldisposed within, and extendlongitudinally of, horizontally elongated housings l2 within the rear ortrailing end of the nacelle 5. Each of these housings consists of a pairof laterally spaced side walls |2a, an outer wall I2b and an inner wallI2C. The outer walls of the housings are connected to the outer marginsof the side walls and have the rear ends thereof suitably secured to thenacelle 5 at points directly in front of the ring shaped stiiener 1.Preferably the side and outer walls of the housings are formed of sheetmetal stampings of channel shaped cross section. The inner walls I2 ofthe housings are suitably connected to the inner margins of the housingsside Walls I2a and are formed of rubber or other resilient material.They serve as dust guards for the housings and have formed thereincentrally disposed longitudinally extending slits I2d through which thenarrow arm-like parts 9ii of the brackets 9 extend slidably. The rearends of the screw shafts I0 are journalled in bearings I3 which extendbetween, and are xedly secured to, the rear ends of the side walls I2aof the housings I2. The front ends of the screw shafts are Ajournalledin bearings I l and these. as shown in the drawings, are disposedforwards of the housings sides I2. The housings I2 are supported withrespect to the nacelle 5 by way of pairs of laterally spaced radiallyextending plates i5, the inner margins of which are connected to theside walls |2a of the housings and the outer margins of which aresuitably connected to the inner periphery of the rear or trailing end ofthe nacelle 5.

g The screw shafts I0 are conjointly turned to effect adjustment orshift of the plug nap 8 by Way of means or mechanism comprising anelectric motor I6, a speed reducing unit I '1, a circular series offlexible shafts I8 and worm and Worm gear driving connections I9. Theelectric motor I6 is preferably located in the bottom portion of therear or tailing end of the nacelle 5 and is suitably supported by abracket structure 20. It is of the reversible type and receives currentfrom an electrical source (not shown) under control of switch mechanism(also not shown) in the f pilots compartment of the airplane A. Thespeed reducing unit I'I is associated with the reversible electric motorI6 and embodies certain gearing which is connected for drive by thearmature shaft of the motor. The gearing includes a transverselyextending driven shaft and is mounted in a casing I'Ia which is joinedto the casing of the motor I I5.` The flexible shafts I8 are rotatablymounted in arcuate tubes 2| and serve operatively to connect the wormand worm gear connections I9 for drive by the driven shaft of the speedreducing unit I'I. As shown in Figure 3, the tubes 2| are arranged in anannular or circular series within the nacelle 5 and are positionedadjacent the front ends of the housings I2. Inwardly ex-` tendingbrackets 22 on the inner periphery of the nacelle serve fxedly tosupport the tubes 2| in their operative position within the nacelle.

'I'he worm and worm gear connections correspond in number to, and areassociated respectively with, the screw shafts 'IIL They are housedvwithin gear boxes 23 on the front endl of the housings I2 and compriseworms I9a and worm gears |91. The worms extend at right angles to thescrew shafts I Il and are xedly connected to stub shafts I9c which arejournalled in, and extend through, the gear boxes 23 and have the endsthereof drivably connected to the ends of the exible shafts I8. The wormgears I9b are fixedly connected to the front ends of the screw shaftsI'IJ and mesh with and are driven by the worms |91. As shown in Figure3, the front ends of the screw shafts ID project beyond the bearings I4and into the gear boxes 23. The flexible shaft that extends between thetwo lowermost worm 'and worm gear driving connections I9 consists of twosections, the adjacent ends of which are drivably connected to thedriven shaft of the speedreducing unit I'I. When the electric motor IBis driven in one direction the screw shafts I0 are conjointly driven inone direction through the medium of the exible shafts I8 and the wormand worm gear driving connections |9 and operate axially to shift theplug ap 8 in one direction with respect to the annular air opening 6.When the electric motor is retion with the driven shaft of the speedreducing unit l1 even though breakage of one of the ilexible shaftsoccurs. The motor IB, the speed reducing unit l1, the flexible shaftsl'8 and the worm and worm gear driving connections I9 constitute simplemeans or mechanism for con-i jointly rotating the screw shafts to effectaxial shift of the plug flap 8.

When the propeller driving engine a2 of the airplane is started while ina cold condition the electric motor I is actuated so as to effect suchdrive of the screw shafts l as to cause the plug iiap 8 to be shiftedrearwards into its closed position wherein it substantially lls orcloses the air opening B between the trailing end of the nacelle 5 andthe front end of the spinner a4. When the plug nap is in its closedposition it so curtails the flow of air through the nacelle that theengine a2 in connection with operation thereof quickly heats. As soon asthe engine is heated to the desired temperature the plug flap 8 isshifted forwards into its fully open or a partially open position so asto permit air to circulate rearwards through the nacelle and thusmaintain the engine a2 at the desired temperature. By axially adjustingthe plug iiap 8 to and from the air opening 6 the flow of air throughthe nacelle may be so controlled as to maintain the engine a2 at anydesired temperature. The herein described engine nacelle, because itincludes the axially shiftable valve type plug nap 8, is highlyefficient and effectively and efficiently fullls its intended purpose.

Whereas the nacelle and associated parts have been described inconnection with a pusher type airplane it is to be understood that itmay be used equally as well in connection with a tractor type airplane,it being clearly manifest that to adapt the nacelle and associated partsfor use with a tractor type airplane it is only necessary to reverse thenacelle and plug ap and locate the screw shafts and brackets adjacentthe trailing rearwardly tapered end of the plug nap. It is also to beunderstood that the invention is not to be restricted to the details setforth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

Having thus described the invention what I claim as new and desire tosecure by Letters Patent is:

l. The combination with an airplane having a spinner equipped propellerand a propeller driving engine adjacent the propeller, of a tubularnacelle extending around and longitudinally of the engine, adapted tohave air flow longitudinally therethrough for engine COOlrlg DUTDOSBSand having the end thereof that is adjacent the propeller ofsubstantially circular contour, fixed, and spaced from the spinner so asto form an annular opening therebetween, and asingle annular plug ap ofairfoil cross section positioned concentrically with respect to, andadapted to control the flow of air through, the nacelle, havingsubstantially the same external and internal diameters as, and disposedin alignment with, said opening, and mounted so that it is shiftableaxially back and forth between an open position wherein it is disposedwholly within the nacelle and a closed position wherein it ts within,and serves by a wedging action substantially fully to close, saidopening.

2. The combination with a pusher type airplane having a spinner equippedpropeller and a propeller driving engine directly in front of thepropeller, of a tubular nacelle extending around and longitudinally ofthe engine, adapted to have air flow rearwards therethrough for enginecooling purposes and having the trailing end thereof of substantiallycircular contour, xed, and spaced from the front end of the spinner soas to form an annular air opening therebetween, and a single annularplug flap of airfoil cross section positioned concentrically withrespect to, and adapted to control the ow of air through, the nacelle,having substantially the same external and internal diameters as, anddisposed in alignment with, the opening, and mounted so that it isshiftable axially back and forth between an open position wherein it isdisposed wholly within the nacelle and a closed position wherein itsfits within, and serves by a wedging action substantially fully toclose, said opening.

3. The combination with an airplane having a spinner equipped propellerand a propeller driving engine adjacent the propeller, of a tubularnacelle extending around and longitudinally of the engine, adapted tohave air flow longitudinally therethrough for engine cooling purposes,and having the end thereof that is adjacent the propeller ofsubstantially circular contour, fixed. and spaced from the spinner so asto form an annular air space therebetween, an annular plug flap ofairfoil cross section positioned concentrically with respect to, andadapted to control the flow of air through, the nacelle, havingsubstantially the same external and internal diameters as, andpositioned in alignment with, the opening and mounted so that it isshiftable axially back and forth between an open position wherein it isdisposed wholly within the nacelle and a closed position wherein it tswithin, and serves by a wedging action substantially fully to close,said opening. and mechanism for shifting the plug ap back and forthbetween said positions disposed in the nacelle and comprising aplurality of rotatably mounted screw shafts arranged adjacent and in acircular series around the plug nap and positioned in parallel relationwith the axis of the flap, nuts mounted on the screw shafts andconnected to said plug flap, a reversible electric motor, and means forconnecting the screw shafts for conjoint drive by the motor, includingan annular series of flexible shafts extending between the motor andsaid screw shafts and around the engine.

DALTON B. SUGGS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2.150,143 Adams Mar. 14, 19392,175,535 Mercier Oct. 10, 1939 2,246,498 Blanding June 24, 19412,270,912 Theodorsen Jan. 27, 1942 2,396,598 Neumann et al. Mar. 12,1946 FOREIGN PATENTS Number Country Date 416,065 Great Britain Sept. 10,1934

